<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<input type="text" id="age" />
<button id="btn">确 定</button>

<script src="http://lib.sinaapp.com/js/jquery/1.9.1/jquery-1.9.1.min.js"></script>
<script type="text/javascript">
    $(function(){

        $("#btn").on("click",function(){
            alert(1);
        });
        //
        //onclick = new function(){
        //  alert
        // }

    });


</script>
</body>
</html>